904 not shifting Help

I recently put a 318 and 904 out of another dart into my s-6 dart. With tranny out I changed the filter and all new fluid adjusted the Kickdown band and the low reverse band according to the Haynes repair manual. Car goes into all gears ok. The problem is in drive frome dead stop taking off up to about 45-50 I don't feel the car shifting. From dead stop in low 1 and shifting manualey car goes into all gears and I can feel it shifting. 1 to 2 shifts fine, 2 - drive a little pause but shift in good. Work fine in the old car. Any help would be greatly appreciated.